piezoelectric-piezomagnetic composite electromagnetic materials have electromechanical, electromagneto and magnetomechanical coupling characteristics, and have become a preferred material to produce sensors, transducers, brakes, memory and recording devices and other electronics. Due to the inherent brittleness of the materials, various defects are unavoidable during the manufacture and use of the devices. Therefore, analysis of the failure of the electromagneto composite materials due to the existence of the defects has become a hot spot for many mechanic workers.
Research on crack issue in piezoelectric-piezomagnetic composite materials and structures has important theoretical significance. Currently, many scholars have studied such problems, including interface cracks in piezoelectric-piezomagnetic materials, interface cracks in two different magnetoelectronic materials, a plurality of interlayer interface cracks in piezoelectric-piezomagnetic and magnetoelectric composite layers, and dynamic impact of single interface cracks etc.
The finite element method is one for discretizing a physical two-dimensional model into a finite set of interconnected elements for analysis and calculation. The method employs continuous function as the shape function, which requires that the shape function in the element is continuous and the material performance can not jump. Therefore, analysis of the discontinuity problems (such as inclusions and cracks) with finite element method is complicated in preprocessing, which requires a special technique for mesh generation, at the same time, its ability to analyze dynamic problems, especially moving boundary problems, is very weak. However, the extended finite element method improves the traditional finite element method based on the idea of unit decomposition, and reflects the discontinuity in the element by adding an enrichment function to the original shape function, so as to analyze the discontinuous problem more conveniently. Meanwhile, since the description to the discontinuous field is completely independent of the boundary of the mesh, it is not necessary to rely on the mesh generation method, this method has great advantages in dealing with the fracture problem.
Accordingly, it is very important to apply the extended finite element method to the analysis of interface cracks in magnetoelectric composites, especially after detecting the structure with a detector, the finite element mesh is divided according to the geometric shape of the structure, and a certain algorithm is applied to calculate the stress, electric displacement and magnetic induction intensity factor at the structure crack, which will be very advantageous to the analysis of the force at the structure crack and provide strong data support for the failure determination of the interface crack of the electromagnetic materials. However, in the prior art, there is no complete method for combining crack detection with extended finite element numerical simulation to analyze fracture characteristics of an interface crack of a magnetoelectric material.